1. Technical Field
The present invention relates to an apparatus and a calculating method of pH.
A pH of a sulfur absorbing liquid which is sea water having absorbed sulfur is around 3. In order to discharge the sulfur absorbing liquid to the sea, the pH must be raised. Conventionally, the pH value has been raised by exposing the sulfur absorbing liquid in the air in an aeration apparatus (for instance, refer to WO No. 2006/018911).
2. Related Art
A guideline related to environmental regulations when discharging the sea water having absorbed sulfur oxides to the sea is established. According to the guideline MEPC 59/24/Add.1, “During commissioning of the exhaust gas cleaning unit(s) after installation, the discharged washwater plume should be measured externally from the ship (while being at anchor) and the discharge pH at the ship's overboard pH monitoring point will be recorded when the plume at 4 metres from the discharge point equals or is above pH 6.5.” The commissioning at the time of installing the exhaust gas cleaning apparatus extends over several days. During the term of the commissioning, various tests such as changing the engine load and operating the exhaust gas cleaning apparatus are performed. During the term of the commissioning, it is thought that a person regularly measures a pH of the position 4 meters from the discharge point, but a human load of this measuring method is large.